While speaking of meeting at an arbitrary date in the future, Karen Mills says to Rockford that "the tide goes out at 7:30." But the tide cycles change every day, saying it goes out at 7:30 like it's always that way is incorrect.
While Rockford follows Michael Cordeen to the Buena Vista Inn, he is listening to the car radio. The dashboard shown is not a Firebird dashboard.
When Rockford is searching through Diana Lewis' dresser drawers in the episode of "Sleight of Hand," he shuts the upper drawer and a piece of clothing is sticking out of it. Then he looks in the other drawers. When the camera switches to him walking away from the dresser, the clothing that was showing is now suddenly missing.
After Mr. Rockford calls emergency services, sirens can be heard within seconds; it is impossible that the call would have transferred through so quickly. It's possible, though, that Jim could've heard the sirens of vehicles responding to a different emergency on the nearby highway.